AVG recently detected 'trojan horse hider mpr' on my laptop. Everytime I try to move it to the virus vault it says that the file is inaccessible and cannot be removed. Since then AVG has not been scanning properly. It will complete in around 1 or 2 seconds and have scanned 0 files. Everytime I try to connect to a website that has avg in it's name access is denied. I have also been unable to run the avg update for presumably the same reason.

AVG never reported any rootkit infection!...Should I still be worried about possible rootkit infection - AVG does not report any infection

This is a known issue, the long story is in the Thread, Unable To Block, Nor Detect MBR Virus. To answer your question, I'll use the famous quote: "...be afraid, be very afraid" if you run on a system as wide-open as Windows. But, be nice, it does keep companies like AVG in business.

BrianOBrien wrote

Anyway I decided on a clean reinstall of XP...

Sorry you had to go through that, considering that a relatively easy remedy was available. I'm trying to catch the new threads to give them the warning. If you agree that this should be a HOT Thread, please respond here, and in the Thread, What Makes "Hot", and can users request it. Thanks.